Sling for swatch

I hit a parked car while backing up just slightly. What will happen to me? - what size is the number plate on a 328i bmw

I pulled back a little, but I accidentally hit the car behind me (a) small I stopped and looked around the car, but my car is again another vehicle hit bummper license, leaving the base car size, slightly smaller than a Pea brand live in my car and no other damage to a car. Since nothing has happened, I went, because he still does not cause any damage to another car, but since the face of an ice cream parlor ... In fear of people, I could write my license plate, even if they have not done damamge another car ....